A report of the Institute of Medicine in 1995 described a number of challenges facing Health Services Research, including the limited availability of crucial data required to describe current trends in health care, and predict and track the consequences of these trends. Just as health informatics research has addressed physicians' and patients' access to and understanding of clinical data and medical knowledge, the field of informatics is well-positioned to address the related information needs issues for researchers. Understanding the information needs of clinicians and patients has been fundamental to the success of informatics research towards developing valuable resources for these information-hungry groups. A similar study of the information needs of researchers will also provide a framework for improving information systems to help researchers access, manage and analyze their data with greater efficiency. Since the outcome of research forms the evidence base used by clinicians, patients and policy-makers, this endeavor will impact many facets of healthcare delivery. The proposed study initiates a series of investigations to examine researcher information needs. This study will analyze the nature of researcher information needs in terms of the kinds of questions posed, the sources used to find answers, the specific data elements sought and the success with which these needs are addressed. Although the specific information needs of researchers are different from those of patients or physicians, the lessons learned through prior informatics work that addressed clinician and patient needs should be valuable in the study of research information needs Similar to early studies of clinician information needs that focused on a single type of provider, this study will limit its examination of information needs to those of the Health Services Researcher. This information needs evaluation will be accomplished through completion of the following specific aims, based on the goals of earlier and more recent studies of information needs: 1) Develop an inventory of research information needs. What questions are being asked, what sources are being used to address the needs, what are the unmet information needs? 2) Determine patterns of association among the elements of the inventory. 3) Describe differences in the inventory of information needs in the 1988-1989 period and 1998-1999 period reflecting the pre-world wide web era and the present time. The significance of this research inquiry is that, analogous to the clinical domain, a greater understanding of research information needs will help to address variation and inefficiencies in the conduct of research, particularly involving data collection, and help create information sources and interfaces that better support the research process.